It is often necessary to remove liquids from paved surfaces. In particular, it is presently the practice to de-ice aircraft by spraying the aircraft with deicing liquids such as glycols while the aircraft are parked on a paved surface such as a taxiway or ramp. The liquid which drains from the aircraft accumulates on the paved surface. This liquid must be collected so that it does not run into storm drains or off the pavement and into the ground water.
It has been proposed heretofore to use a high-powered vacuum cleaner mounted on a special-purpose truck chassis with its own motive power to collect the liquid. Units which have been available prior to the present invention have required very powerful suction units, which are costly to build and to operate. The special-purpose truck chassis, with its own power train, adds further cost. Attempts have been made heretofore to use suction cleaning units mounted on trailers which can be pulled by an ordinary truck. Moreover, the fluids tend to accumulate on the pavement in uneven pools, with shallow and deep portions. The suction cleaner may work well on deep liquid as, for example, a pool more than an inch deep, but work poorly on shallow liquid or vice-versa.
Accordingly, there have been needs for further improvements.